Polycystic ovary syndrome is a reproductive endocrine disorder characterised by combinations of ovulatory dysfunction, clinical or biochemical androgen excess and polycystic ovarian morphology. It appears to be more common in women with epilepsy, but the relationship involves both epilepsy biology and treatment.
PCOS is not the same as polycystic ovaries
Polycystic ovarian morphology on ultrasound does not by itself establish PCOS.
Modern diagnostic frameworks require a broader clinical and endocrine assessment and exclusion of alternative causes.
The association with epilepsy is supported but heterogeneous
A 2026 systematic review and meta-analysis of 28 studies estimated a pooled PCOS prevalence of about 19% among women with epilepsy and reported higher odds than in control populations.
The studies were highly heterogeneous, so the pooled number should not be treated as an individual prediction.
Valproate is an important part of the story
Valproate has long been associated with weight gain, hyperandrogenism, menstrual disturbance and PCOS-like endocrine changes in some women.
A 2025 nationwide Danish cohort also found an increased PCOS risk with valproate exposure, strengthening the association beyond older small studies.
Epilepsy itself may influence reproductive endocrine function
Temporal-limbic and hypothalamic networks influence gonadotropin-releasing hormone and pituitary signalling.
Research suggests that seizures and interictal epileptiform activity may alter hypothalamic-pituitary-ovarian regulation independently of medication.
Symptoms deserve active screening
Irregular or absent periods, acne, hirsutism, unexpected weight change and fertility difficulty can be clues.
These symptoms should not automatically be blamed on an antiseizure medicine; proper endocrine evaluation is needed.
Why PCOS matters beyond fertility
PCOS can be associated with insulin resistance, metabolic risk and endometrial consequences from chronic anovulation.
Recognising it therefore matters even when pregnancy is not currently planned.
Treatment decisions require balance
If valproate is contributing to endocrine problems, changing medication may be considered when clinically appropriate.
However, seizure control and the risks of alternative medicines must be weighed carefully; antiseizure treatment should not be stopped abruptly.
Related reading
Sources and further reading
- PCOS prevalence and risk in women with epilepsy — 2026 systematic review/meta-analysis
- Valproate exposure and PCOS — nationwide 16-year cohort
- Female sex steroids and epilepsy, Part 1 — 2024 review
Evidence checked: September 2026.